def add(a, b):
    return a + b

def subtract(a, b):
    return a - b

def multiply(a, b):
    return a * b

def divide(a, b):
    return a / b

operations = {
    "+": add,
    "-": subtract,
    "*": multiply,
    "/": divide
}

def compute():
    n1 = float(input("What's the first number?: ")) 

    for sign in operations:
        print(sign)


    while True:
        operation_sign = input("Pick an operation sign from the line above: ")
        n2 = float(input("What's the next number?: "))
        result = operations[operation_sign](n1, n2)

        print(f"{n1} {operation_sign} {n2} = {result}")
        n1 = result
        if input(f"If you want another operation with {n1} type 'y', for start calculation from begining type 'c' and type 'n' for stop calc: ") == "c":
            break
        else:
            compute()

print("Bye, bye!")